Machine for grinding gear-generating cutters.



No. 686,599. Patented Nov. I2, [90L E. R. FELLOWS. I MACHINE FORGRINDING GEAR GENERATING CUTTERS.

, (Application filed June'24, 1899.) (No Model.) I ll Sheets-Sheet l.

EEI' INVEV/ZNTEIRZ Patented Nov. I2, 19m.

E. B FELLOWS. MACHINE FOR GRINDING GEAR GENERATING GUTTERS.

(Application filed June 24, 1899.) I

ll Sheets-Sheet 2.

(No Model.)

INVENTEI R a z 'm/ i w gmrzasrzsz No. 686,599. Patented Nov. I2, I90I.E. R. FELLOWS. MACHINE FOR GRINDING GEAR GENERATING CUTTEBS.

(Application filed June 24, 1899.)

ll SheetsSheet 3.

(No Model.)

. S. I ill. II: I i

- 7 Patented Nov. l2, I901 E. R. FELLOWS. MACHINE FOR GRIND ING GEARGENERATING GUTT (No Model.)

EBS.

(Application filed June 24, 1899.)

ll Sheets-Sheet 4 i "T IIHHI llnlfi lll III M 1 I "a i J TUBA-YINVENTDR: 6M 6 541% No. 686,599. Patented Nov. I2, I90l. E. R. FELLOWS.

MACHINE FDR GRINDING GEAR GENERATING CUTTERS.

(Application filed June 24, 1899.)

Patented Nov. l2, I901.

E. R. FELLOWS. MACHINE FOR GRINDING GEAR GENERATING GUTTERS.

(Application filed June 24, 1899.)

ll Sheets-Shoet 6.

(No Model.)

'INVENTEIRI W QZLM No. 686,599; Patented NOV. I2, I90I. E. R. FELLOWS.MACHINE FOB GRINDING GEAR GENERATING CUTTERS.

(Application filed June 24, 1899.)

(No Model.)

ll Sheets-Sheet 7.

.R mi 3mm; 5 5 7 WITN E55 E51 Patented Nov. l2, I9OI.

E. n. FELLOWS. MACHINE FOR GRINDING GEAR GENERATING CUTTERS.

(Application filed June 24, 1899.)

II Sheets-Sheet 8 (No Model) u m .0 Er M 2 6 A W 0 5 My 5 5 5m. 5 W2 No.686,599. Patented Nov. l2, I90l. E. R. FELLOWS. MACHINE FOR GRINDINGGEAR GENERATING CUTTEIIS (Application filed June 24, 1899.)

II Shee'ts-Sheet 9.

(No Model.)

INVENTEI R ww ufl k zm v\X/l-rm ESSESZ m @f y No. 686,599. Patented Nov.l2, I90I. E. R. FELLOWS. MACHINE FOR GRINDING GEAR GENERATING GUTTERS.

(Application filed June 24, 1899.)

II Sheets Sheet I0.

(No Model.)

INVENTEI R;

WITNESSES; I @WWW Patented Nov. I2, I90I.

E. R. FELLOWS. MACHINE FOR GRINDING GEAR GENERATING CUTTERS.

(Application filed June 24, 1899.)

II Sheets$heet ll.

(No Model.)

\IIIIIIIIIIWIII UNITED EDWIN R. FELLOWS, or SPRINGFIELD, VERMONT.

MACHINE FOR GRINDING GEAR-GENERATING CUTTERS PATENT, OFFICE.

SPECIFIGATTON forming part of Letters Patent No. 686,599, November 12,1901.

Application filed June 24', 1899.

metal-planiu g cutter havinga continuous circular series of radiating oroutwardly-projectihg metal-planing teeth of uniform size, whose cuttingedges are at the ends of the teeth on the face of the cutter, the backsof the teeth being inclined ataslight clearance- .angle to the axis ofthe cutter to give the cutter the clearance of metal-planing tools.

A cutter of the character specified is adapted for use ingenerating-gears by the method described in United States Letters PatentNo. 579,708, granted to me March 30,1897, which show a machine in whichare combined a metal-planing cutter having a circular series ofradiating or outwardly-projecting gearshaped metal-planing teeth, ablank holder provide a machine for finishing cutters of the characterdescribed-that is, for treating a cutter blank which has had its teethpreviously roughed out and hardened in such a manner as to bring saidteeth to their correct size and shape. The invention-is 'not, however,limited in its application to finishing gear-shaping cutters, as it mayalso be employed in grinding the teeth of bevel and other gears whichhave been hardened and are hence diflicult to attack bymeans of ametal-planing tool.

The invention involves the employment of an abrasive generating-wheel, aholder for the line 3 3 of Fig. 1.

Serial For 721,711. (No model.)

the cutter, means for imparting a rolling motion to said holder to causeit to roll over and bring one of its teeth to contact with the face ofthe generating-wheel, whereby the side of the tooth is ground to itscorrect curvature, and means for indexing the cutter-holder or turningit on its own axis to bring the teethof the cutter successively intoposition to be Tic ground.

Of the accompanying drawings, Figure 1 represents a front elevation of asimple form of machine embodying my invention. .Fig. 2 represents a planview thereof. Fig. 3 represents a longitudinal section therethrough onFig. 4 represents a front elevation, partly .in section,-showing a moreelaborate embodiment of my invention in the'form of an automaticmachine, the cutter being shown as retracted from the grinder. Fig. 5represents a view similar to the foregoing with parts in section, thecutter being shown in contact with the grindeiu, Fig. 6 represents aplan view of the machine. Fig. 7 represents a rear elevation with partsbroken away and parts in section. 1 Fig. 8 represents;' a-sectionon line8 8 of Fig. 5.. Fig. 9 repre sents a right end elevation. Fig. 10repre-j sents a detail plan view of the cylindrical '80 roller and tapesgoverning the cutter-spindle. Fig. 11 represents a transverse sectionalview of said roller with its slide and adjacent parts. Fig. 12represents a left end elevation of the machine. Fig. 13 represents adetail plan 8 view of the diamond holder and adjacent parts employed infacing the grinder, said device being omitted in certain previousfigures for the sake of c'le'a'rness. Fig. 14 represents a sideelevation of said parts. Fig. .15 repre- 9o sents a view correspondingto Fig. 11, showin g a modification, hereinafter referred to, for movingthe roller tape-bars v The same reference characters indicate the sameparts in all the figures. 5 Referring for the present to Figs. 1, 2, and3, a-designates the base or frame of the machine, and b designates thespindle'or arbor,

to the end of which the, cutterc is clamped? The cutter is held betweenasho'ulder b? on the spindle and a ring-or washer b ,"against which anut b3, engag'ing the threaded end of the spindle, is-screwed. H ddesignates a generating-wheel,such'as an emery-wheel, for grinding thecutter-teeth,

said wheel having an edge thin enough to The cutter c is of the formreferred to,

having radial or outwardly-projecting gearshapcd teeth 0' c, the cuttingedges of which are on their front ends 5 and the crests 6 of which areinclined at a slight angle to the axis of the cutter, giving the'teeththe clearance of ordinary metal-planing tools, while the sides 7 of theteeth when ground will have a convergence which gives them sideclearance, there being thus imparted to the cutter the general form of abevel-gear. The large end of the cutter is preferably slightly dished togive the teeth the ordinary rake of metalplauing tools.

In carrying out my invention as hereinafter described I employ theprinciple of generating an involute tooth by the action of an imaginaryrack having teeth of the form of a truncated wedge. The face 2 of theemerywheel d corresponds to the side of one tooth of the rack.

The spindle b, which carries the cutter, is mounted in an elongatedbearingsleeve b, which has two conical surfaces 3 and 4 turned on itnear its front and rear ends and forming parts of the pitch-cone of thebevel-wheelshaped cutter. These surfaces are adapted to roll on two flatbars a a attached to the frame aand forming a supporting plane surfacefor the cone, and between the conical surfaces and the bars areinterposed two pairs of thin flat tapes or bands e e e e, preferablymade of steel, so as to be inextensible and attached at their inner endsto the sleeve 11' by screws e e and at their outer ends to the bars a aby screws e e. \Vhen rolling motion is imparted to the sleeve, one tapein each set winds up on the sleeve while the other tape unwinds, thuscausing said sleeve and the cutter to turn on their own axis, theresultant being a rolling motion with the apex of the pitch-cone as acenter. During this movement the axis of the spindle b generatesaconical surface. Endwise play of the sleeve is prevented by a spring bsurrounding the same and abutting at its rear end against a shoulder onthe sleeve and at its front end against a loose collar D which abuts thetapebar a b is a collar keyed to the rear end of the sleeve 12', and bis a handle projecting therefrom and adapted to be grasped to impart therolling movement to the sleeve. Said rolling movement results inreciprocating the cutter c toward and from the emery-wheel d. On themovement of the cutter toward the emerywhcel the side of one of itsteeth 0 will roll over int-o contact with the face 2 of said wheel,

and the latter will grind an involute surface thereon. If the uppersurfaces of the tapebars a 0!. were parallel to the axis of the emerywheel, the curve generated on the tooth would be that mating with a rackhaying square teeth or teeth of no angle; but in order to give thecutter-teeth their proper obliquity I incline the tape-bars at an acuteangle to the axis of the emery-wheel, as shown in Fig. 1, which isequivalent toinclining the imaginary rack of which the emery-wheelrepresents one tooth; When the emery-wheel reaches the root of thecutter-tooth, its face 2 is radial with the center of the cutter c, asrepresented in Fig. 1. 4

On the rear end of the cutter-supporting spindle bis secured anindexing-wheel f, provided with teeth around its periphery meshing witha worm f,' having a spindle f, mounted in hearings on a bracket b, whichdepends from the collar 1), rigidly keyed on the sleeve b. For rotatingthe worm a short crank f is attached to its spindle, said crank carryingat its end a locking-pin f adapted to enter a hole in a projecting bossb on the collar 1) to lock the worm. Each time the cutter c'is rolledback out of contact with the emery-wheel the locking-pin f is withdrawnand the index-wheel f rotated to turn the spindle b on its axis andbring a fresh tooth of the cutter into position to be ground. The

pitches 0f the index-wheel and of the worm are so related that a givennumber of revolutions of the crank f will step the cutter ahead exactlyone tooth and the locking-pin is employed to fix the cutterin theposition thus determined. The stepping of the cutter ahead after eachcontact with the emerywheel is continued until it has made a completerotation and has had one side of each of its teeth ground. The grindingof the opposite sides of the cutter-teeth is preferably done on anothermachine having an arrangement of emery-wheel and inclined tape-bars thereverse of that on the machine described; but the parts of the presentmachine may obviously be made adjustable, so that all the grinding canbe done on the one machine.

It will be evident from the foregoing description that thegrinding-machine illustrated in Figs. 1, 2, and 3 may be employed ingrinding hardened bevel-gears as well as gear-shaping cutters. Cuttersof the kind under consideration are usually narrow, and in grinding themit is not found necessary to efiect any relative longitudinal motion ofthe emery-wheel as a whole and the cutter. The wheel merely sweeps overthe surface of the cutter-tooth; but in adapting the machine forgrinding bevel-gears I prefer to mount the emery-wheel in a movablebearing, such as shown in the drawings, so that the wheel as a whole canbe moved along the tooth of a wide gear to grind the whole length ofsaid tooth. For this purpose the bearing or sleeve (1 supporting theemery-wheel is mounted to slide forward and back on a guide (1 on theframe a and is provided with a rack 01 whose teeth mesh with those of astationarily-mounted pinion (1, turned by means of a handle d.

Having explained the elements and operation of my invention by thedescription of a simple hand-operated machine constructed in accordancetherewith, I now proceed to the consideration of an automatic machineembodying the invention and differing in the action of its working partsonly by the substitution' of a cylindrical roller carrying thecutter-holding spindle for the conical roller.

of the machine just described and the setting of' the grinding-wheelwith its plane at a slight angle to the axis of said roller to give thecutter-teeth their angle of side clearance.

liteferring to Figs. 4 to 12, a. is the machines frame or base, theupper portion of which only is shown.

b is the cutter-spindle, having aholder on its end in which the cutter cisclamped, and dis the grinding-wheel, having an acting face ,2 in aplane at right angles to its axis of rotation. The spindle b is carriedin a bearingsleeve 12", having a cylindrical portion 8, to which areattachedoppositely-wound tapes e e, having their outer ends secured toflat-' topped tape-bars a 0. The latter are bolted to the frame in aninclined position, as shown. The bearing-sleeve b is mounted in a slideb, which is adapted to reciprocate in a rectilinear path of aninclination corresponding to that of the tape-bars on a suitable guideon the frame a. The slide is reciprocated by means of abell-crank leverb, one of the arms of which'is connected by a link b with the slide, theother arm being connected by a link b with-a crank b" ona'continuouslyrotating cross-shaft I), mounted in suitable hearings onthe frame.

a worm-gear b at its end, meshing with a .worm g on the main drive-shaftg of the machine, which latter is equipped with a cone Said cross-shafthas belt-pulley g. It is evident that the reciprocation of the slide bgives the cutter 0, through the control exercised by the tapes e e,

' the motion required to roll it from the retracted position representedin Fig. 4 over into contact with the grinding-wheel d, as shown in Fig.5, and back again, causing the grinding-wheel to generate an involutesurface on the side of each tooth of the cutter,

the cutter being automatically stepped forward or indexed, one tooth oneach backward stroke, by indexing mechanism presently to be described.

The spindle d of the grinding-wheel has a belt-pulley d on its rear end,whereby. it may be rotated and is mounted in a bearing-sleeve d", whichis set so as to incline 'the plane of the acting face 2 of said wheel ata slight angle to the axial line of the cutter-spindle, as

represented in Fig. 6, and thereby cause saidwheel to grind the sides ofthe cutter-teeth with a slight convergence to give the teeth theirside-cutting clearance.

By means of this machine cutters such as which a vertical adjustment maybe given ters Patent, Serial No. 721,712, filed by me 1 June 24, 1899,can be ground. Said applica- 7o tion describes a cutter having anendless circular series of radial or-o'utwardly-projecting metal-planingteeth, the sides of which converge in the direction of their length andare of equal curvature throughout-that is, supposing the teeth of thecutter to be involute teeth, the side outlines. of a tooth at differentpoints along the length of the tooth will be involutes drawn tobase-circles of equal diameter. In this machine the grinding-wheel isset so that its plane will follow the convergent lines of 'the sides ofinvolute teeth and will grind the involute surface and be when incontact tangent thereto. 1

The sleeve cl is carried by a slide d to y a hand-screw (Z to varytheelevation of the grindingwheel, and said slide and handscrew are in turncarriedbya plate (1 A mounted to slide on the side of the frame 01. 9oinithe arc of a circle whose center is at the point occupied by thecenter of the cutterspindle b when at its forward extreme of position,Fig. 5. By this adjustment the angle of obliquity of the grinding-wheelwith re- 5 spect to the cutter may be varied. The plate d is clamped tothe frame a by bolts cl d", the bolt d also serving to clamp the slide(1 in position. A segmental tongue (1 on the frame a, fitting in acorrespondingly-shaped 10o .groove in the plate (1, serves to'guide saidplate. A third adjustment is'p'rovided for the grinding-wheel d bymounting the bearing-sleeve at so as to be capable of sliding ontheslide (1 in the direction of the axis of .105 the wheel, its positionbeing regulated by means of an. adjusting-screw d", against the headofwhich the sleeve is pressed bya spring] d This adjustment is employedwhen the) face of the grinding-wheel is trued up by the 1 1o diamond.(Illustrated in Figs. 12, 13, and 14.) The holder or bracket h'forthe-diamond h is mounted on top of the slide (1 carrying the grindingwheel (1, but is normally swung aside on its pivot-bolt k to theposition shown in broken lines in Fig. 13. When it becomes necessary,however, to true up the acting face of the emery-wheel (I, so as to keepsaid face a perfect plane, the cutter-operating mechanism is stopped andthe bracket h is swung around and fixed in lace with the bolt h and anadditional bolt as represented in full lines in Figs. 12, 13, and 14.Thediamond h should be so adjusted in its bracket that when thuspositioned it coincides with the proper plane of the emery-wheel face 2.Said Wheel is moved bodily in the direction of its axis by adjusting thescrew (1" to bring the face 2 slightly past this plane, and the diamondis then inoved inwardly in a radial 1 0 direction over the face of theemery-wheel by manipulating a screw .72., which projects a slide h onwhich the diamond is mounted.

The diamond grinds off the surface of the wheel and reduces the face 2to a true plane. Lateral adjustment of the diamond may be effected whenrequired by manipulating a nut h.

I will now describe the indexing mechanism for rotating the cutter toothby tooth on its own axis. This rotation takes place after the motion ofthe slide b has withdrawn the cutter from contact with the emery-wheeland occupies about one-third of the operating time.

f is a large index-wheel attached to the rear end of thecutter-supporting spindle b and formed with teeth on its periphery whichmesh with a worm f, carried in bearings on an arm or bracket Z2 rigidlykeyed to the rear end of the sleeve b, which supports the spindle I).Said bracket in practice is suitably counterweighted to balance themechanism carried by it. On the shaft of the worm if is a gear f meshingwith a gear f, on

whose shaft is a gear f meshing with a gear f all carried by the bracketI). The shaft of the last-said gear terminates in a universal joint j,which connects it with the inner section 9 of a telescopic shaft f". Theouter tubular section 10 of said shaft is splined to the section 9, sothat the two rotate together, and is connected bya universal joint f toa short shaft f, which is driven intermittently through gears f f f" f,segmental gear f and bevel-gears f from the continuously-rotatingcross-shaft b. The gears f 5 f are change-gears,which may havevariouslyrelated diameters, according to the pitch of the cutter whichis to be ground. The segmental gear f gives the gears f and f 17 onecomplete rotation in its passage across the former of them, and they inturn give the worm f a certain number of rotations and cause theindex-gear f on the end of the cutter-spindle to make a predeterminedfraction of a rotation, the amount of which depends upon the relation ofthe change-gears f f To the bracket 12" is aflixed a segmental scale orindex f over which a pointer f, mounted alongside of the gear f isadapted to sweep. The collar f, Fig. 7, which bears the pointer, isnormally loose on the shaft of the worm f and gear f but may be securedthereto by means of a thumb-screw f The pointer and scale are used tocalibrate the cutter. In calibrating the thumb-screw f is set up, thegear f 'is loosened on its shaft by throwing over a clamping-lever f andthe pointer'is ,moved a predetermined distance across its index, whichdistance gives a known equivalent rotary movement to the cutter.

It now remains to consider the device for locking the indexingmechanism.

When the cutter has rolled back two-thirds of its stroke away from theemery-wheel and is out of contact therewith, the locking-pin included insaid device is automatically withdrawn and the mutilated gear comes intoaction and rotates the indexing-worm, which rotation continues for theremainder of the back stroke of the cutter and for one-third of itsreturn stroke, after which the said locking-pin again becomes engagedand locks the indexing mechanism. On the same shaft with the gears f andf is a disk 1'', having a segmental portion of its periphery cut away toform two stops or abutments 15 16, with which two shoulders 13 14,located at right angles on a locking-pin i, I are adapted to becomeengaged, thereby locking said disk, and hence the worm f from rotationin either direction. The pin i is mounted in guides on the bracket b andis normally pressed by a spring '6 into engagement with the notched disk11'. Release of the pin is efiected by the intermittent action of a dog1', mounted on a short shaft '5 carried by the bracketb and terminatingin a universal joint which connects it with the inner section 11ofatelescopicshaft t'". The outer tubularjsectionlt? of said shaft issplined to the innersection, so that the two rotate together, and iscarried in a tubular bracket i pivoted at 1 to a stud on themachine-frame a. Said outer section 12 of the shaft is provided withshoulders at either end outside of its bearing in the socket i so as tobe incapable of moving longitudinally therein, and on its rear end isfixed a segment of a bevel-gear 2', whose teeth mesh with a bevelgearsegment 11, formed on a plate 1?, which has the shape of a bell-crankand is pivoted on the stud 7: A cam 1' screwed to the side of thewormgear b, and hence revolving with the shaft b, engages a roll 1? onthe bell-crank once in every revolution of said shaft and by suchengagement oscillates the bell-crank, rotates the telescopic shaft, andwithdraws the locking-pin 'i.' As soon as the cam 2' leaves the roll 1the pin is returned by its spring into locking engagement with the disk'11.

In Figs. 4, '6, 7, and 8 the parts of the machine have the positionswhich they occupy when the cutter is rolled back away from theemery-wheel. As the cutter moves forward up its incline the bracketlFandall the parts carried thereby are swung upwardly, so as to occupy theposition shown in Fig. 5 when the cutter reaches the limit of itsforward movement. During this oscillation of the bracket the telescopicshafts connecting the fixed gearing with the mechanism on the bracketwill become extended.

It is evident that with the machine asthus far described cutters of butone diameter of pitch-circle can be ground, said diameter being that ofthe cylindrical portion 8 of the cutterspindle roller plus the thicknessof the tapes 8 a. pitch, the roller might be provided with cylindricalportions of different diameters and corresponding tapes and tape -bars,which bars run loose except when in use, or a mechanism for moving thetape-bars may be pro- IIO To grind cutters.of a different vided such asthat illustrated in Fig. 15. The

are connected'by a link e with a bell-cranijrl e", pivoted at e to theframe.

a" is' a slide-i way or guide mounted on an ear b on the, slide b andadapted to be fixed at difierent angles thereon. An arm of thebell-crank e is pivoted to a block e, sliding in the groove of saidguide, and the travel of the slide b has by this connection the effectof oscillating the bell-crank and moving the tape-bars in the directionof their length- By varying the angle of the guide e this movement ofthe bars ma; be made greater or less, and bysetting the guide e"angnlarly to either one side or the other of the path of its movementthe bars may be'caused to travel either in the same direction as theslide 1) or opposite thereto. It isevident that the former move-. meutwill be equivalent to increasing the diameter of thepitch-circle onwhich the cut ter rolls, while the latter movement will be equivalent todecreasing the pitch-circle. By substituting a curved guide for thestraight guide e'and a rollfor the block e ,a' varia- .tion' 61. thecurve ground on the cutter-tooth may be obtained. 7 In this machine, asin the one illustrated-in Figs. 1, 2, and 3;,only one 7 side of each ofthe-cutter-teeth is'ground;

To grind the other'sides of the teeth, a machine is employed having aconverse. ar

rangement-that is, having its slide inclined in an opposite directionto' the slide b t'aud I The principles of construction employed in thegrinding-wheel di faced theiotherway. This arrangement would be obtained"by mounting the mechanism located 'onthe front of the,machine,as shown,on thebackof the machine and, conversely, bringing'the'ciitter at theother, end of its spindle.

the machine could be embodied in a machine for grinding the teeth ofspur-gears by setting the grinding-wheel with its plane parallel to theaxis of the cutter-spindle, and preferably giving either the gear or thegrinding-wheel a movement longitudinally of the gear-teeth.

It willbe noted. that the first-described embodiment of; my inventiondifiers from the second in that the-former grinds, surfaces on thecutter-teeth which are those of a true bevel-gear in which thebase-circles of the involutes decrease in diameter as they approach theapex of the gear, whereas, the latter grinds involute surfaces, allportions of which have the, same base circle or cylinder, although thegeneral form of the completed cutter is that of a section of a flutedcone. The rela-.

. tive movement of the .blankand grindingwheel in the latter embodimentis that of a rack and pinion of the spur-gear system havholder, saidmechanism having provisions forrelatively moving said wheel and holderin a relation wherein the grinding-wheel generates the curved outlinesof gear-teeth on a blank held in the holder;

on hardened toothed blanks,a rotatable grinding-wheel, ablank-holder,xand means for imparting a relative movement to the two inthe relation of intermeshing gears. n -3. In a machine for generatinggear-teeth 0n hardened toothed blanks, the combination of agrinding-wheel, a blankholder, andme'ans for rolling the blank-holdertoward and from the edge of the grindin wheel, to generate the side of amomen 'lank by abrasio'n against the wheel; i v v 4. Ina machine fong'enrat ng gear-teeth on hardened blanks,v the bination of a blank-holder,a' grinding+wheel, and means for imparting a relative movement to thetwo in the relation of spur system. 4

5. In a machinefor g onhardened blanks, th blank-holder, a grindingtoicorrespond to a skewe nerali gig gear-teeth el set an gularly t andmeans in the relation of intermes ing gea'mof the spursystem.

on hardened toothed blanks,=the combination :of a grinding-wheel havinganactingface at right a'ngles'to its axis, a 'blankholder, and means forrolling the blank-holder toward and on hardened toothed blanks, thecombination of a grinding-wheel, a blank-holder, "and means for rollingthe blank-holder toward and from the edge of the grinding-wheel with itsaxisfin parallelism at an angle to the axis of the'cutter. v

9. In a machine for generating gear-teeth on hardened toothed blanks,the combination ofa grinder, a blank-holder, a spindle supporting thelatter, a bearing for said spindle,

from the grinder, a gear-wheel on said spindle, and mechanism carried bysaid bearing and engaging the gear-wheel for rotating the spindle in itsbearing.

10. In a machine for generating gear-teeth on'hardened toothed blanks,the combination 2. In a machine for generating gear-teeth I intermeshinggears of the for imparting a relative me ement tofthe two 8. In amachine for generating gear-teeth means for rolling said bearing towardand.

ism. forpositively controlling the wheel and mbinatlon of a- 6. In amachine for generating gear-teeth from the edge of the grinding-wheel ina path of a grinder, a blank-holder, a spindle supporting the latter, abearing for said spindle, means for rolling said bearing toward and fromthe grinder, a gear-wheel on said spindle, mechanism carried by saidbearing and engaging the gear wheel for rotating the spindle in itsbearing, a driving member mounted in a stationary bearing, and aflexible and extensible rotary connection between said member and saidmechanism.

11. In a machine for generating gear-teeth on hardened toothed blanks,the combination of a grinder, a blank-holder, a spindle supporting thelatter, a bearing for said spindle, means for rolling said bearingtoward and from the grinder, a gear-wheel on said spindle, mechanismcarried by said bearing and engaging the gear wheel for rotating thespindle in its bearing, and means for locking said mechanism.

12. In a machine for generating gear-teeth on hardened toothed blanks,the combination of a grinder, a blank-holder, a spindle supporting thelatter, a bearing for said spindle, means for rolling said bearingtoward and from the grinder, a gear-wheel on said spindle, mechanismcarried by said bearing and engaging the gear-wheel for rotating thespindle in its bearing, a lockin g device carried by said bearing forlocking said mechanism, a movable member mounted in a fixed bearing foroperating said device, and a flexible and extensible connection betweensaid member and said device.

13. In a machine for generating gear-teeth on hardened toothed blanks,the combination of a grinder, a blank-holder, means for rolling saidholder goward and from the grinder, mechanism for :otating the holder onits axis independently of its rolling motion to index the blank, a c'ntinuously-rotating shaft, and a part drive thereby and operatingintermittently on said mechanism, for driving the mechanism 14. In amachine for generating gear-teeth on hardened toothed blanks, thecombination of a grinder, a blank-holder, means for rolling said holdertoward and from the grinder, mechanism for rotating the holder on itsaxis independently of its rolling motion to index the blank, 2. lockingdevice for locking said mechanism, a continuously-rotated shaft,and apart driven thereby and operating intermittently on said locking device,for actuating the same.

15. In a machine for generating gear-teeth on hardened toothed blanks,the combination of a grinder, a blank-holder, a spindle supporting thesame, a bearing therefor, means engaging said bearing for causing axialrotation thereof when lateral movement is imparted to it, a slidecarrying said bearing, and means for reciprocating said slide, wherebythe blank-holder is caused to roll toward and from the grinder.

16. In a machine for generating gear-teeth on hardened toothed blanks,the combination of a cutter-holder, means for imparting a reciprocatingrolling motion thereto, a grindingwheel, a bearing journaling saidwheel, and means for adjusting said bearing in the arc of a circle whosecenter is a point reached by the axis of the cutter-holder in itsreciprocation.

17. In a machine for generating gear-teeth on hardened toothed blanks,the combination of a cutter-holder, means for imparting a reciprocatoryrolling motion thereto, a grindingwheel, a bearing journaling saidwheel, a member supporting said bearing and adjustable in the are of acircle whose center is a point reached by the cutter-holder in itsreciprocation, and means for adjusting the bearing on said member tomove the wheel radially with respect to said point.

18. In a machine for generating gear-teeth on hardened blanks, thecombination of a blank-holder, a grinding-wheel representing agenerating gear-tooth, means for imparting a relative movement to saidholder and grinding-wheel in the relation of intermeshing gears, and adevice for truing the surface of the grinding-wheel, said device beingmounted for movement in the generating-surface, and the grinding-wheelbeing mounted for movement of its generating-face toward said device.

19. In a machine for generating gear-teeth on hardened toothed blanks,the combination of a cutter-holder, a bearing-therefor, means forimparting a lateral reciprocatory movement to said bearing, a memberhaving a connection with said bearing causing it to roll when thusreciprocated, and means for moving said member longitudinally at apredetermined rate during the reciprocation of the bearing.

20. In a machine for generating gear-teeth on hardened toothed blanks,the combination of a cutter-holder, a bearing therefor, means forimparting a lateral reciprocatory movement to said bearing, a memberhaving acounection with said bearing causing it to roll when thusreciprocated, means for moving said member longitudinally at apredetermined rate during the reciprocation of the bearing, andprovisions for adjusting said means to vary the rate of movement of saidmember.

21. In a machine for generating gear-teeth on hardened toothed blanks,the combination of acutter-holder, a bearing therefor, means forimparting a lateral reciprocatory movement to said bearing, a memberhaving a connection with said bearing causing it to roll when thusreciproeated, means for moving said member longitudinally at apredetermined rate during the reciprocation of the bearing, andprovisions for reversing said means to produce said movement in the samedirection with the movement of the hearing,

or opposite thereto,

22. In a machine for generating'gear-teeth on hardened toothed blanks,the combination of a cutter-holder, a bearing therefor, a slide carryingsaid bearing, means for reciprocating said slide, a member having aconnection with said bearing causing it to roll when thus reciprocated,a lever connected with said member, and a guide on the slide engagedwith said lever.

23. In a machine for generating gear-teeth on hardened toothed blanks,the combination of a cutter-holder, a bearing therefor, a slide carryingsaid bearing, means for reciprocating said slide, a member having aconnection member, a guide on the with said bearing causing it to rollwhen thus reciprocated, a lever connected with said EDWIN R. FELLOWS.

Witnesses:

WILBUR A. LEONARD, E. J. FULLAM.

slide engaged with 15

